The present invention relates to an electronic musical instrument.
As is known in the prior art, one form of electronic musical instrument stores a digital representation of an analog musical sound such as an organ, a drum, or other type of musical instrument. The sound is typically stored in a read only memory (a "sound" ROM) and the sound ROM is addressed by a counter with the digital representations being serially read out of the memory and connected to a digital to analog converter (DAC). The resulting analog waveform is then connected to an audio output channel and to a conventional audio speaker, whereby the resulting analog sound is an accurate presentation of the digital signal stored in the ROM.
In order to provide for multiple sounds, the prior art approach has typically utilized a separate ROM and separate counter for each sound with the resulting digital signals being transmitted to separate DACs or in a time division multiplex (TDM) format for connection to a single DAC. The resulting analog waveform from the single DAC is then demultiplexed to the appropriate audio channels.
Such prior art approaches are illustrated in U.S. Pat. Nos. 3,763,364 and 4,305,319. A problem with such approaches is that in order to provide for generation a plurality of musical sounds accurately, the equipment is necessarily more complex (and expensive) because of the additional hardware and/or software requirements.
It would be highly desirable to provide an improved electronic musical instrument which would reduce the hardware complexity of the prior art while still providing for faithful reproduction of the desired musical sounds to be played simultaneously.
It is therefore an objective of the present invention to provide an electronic musical instrument which improves on the deficiencies of the prior art as described above.